AUGUSTA, Maine — Angus King was a lifelong Democrat best known as a television host before he unenrolled from his party and went on to win what looked at the start like an improbable run for Maine governor.

“The Democratic Party as an institution has become too much the party that is looking for something from government,” he told the Bangor Daily News after announcing his 1994 bid.

Next year, the independent U.S. senator elected in 2012 after two terms as governor from 1995 to 2003 may enter his last campaign. Unlike 1994, when he ran hard against the Democratic establishment, he’s already being portrayed as a legacy “Democrat” in his 2018 re-election bid.

King, 72, who declined an interview request through a spokesman, is arguably Maine’s most prominent left-of-center voice, especially after the era of Gov. Paul LePage has broken the hold that Democrats had here for decades before the Republican governor’s 2010 election.

LePage is teasing a run against King, with state Sen. Eric Brakey, R-Auburn, on the verge of announcing his own bid. Either would have a hard race against the popular King, who has steadily won over Democrats during his career while holding onto the political middle and the independent brand that many Republicans don’t buy.

King campaigned hard against the Democratic establishment at first, but he won over many of the party’s voters and some of its leaders. His foray into politics, after a legal and business career and 17 years hosting “Maine Watch,” a public broadcasting interview show, was aided by the fact that he was running against two imperfect major-party opponents.

In 1994, former two-term Democratic Gov. Joseph Brennan coasted to a primary win but faced criticism for being past his political prime, while a 41-year-old Susan Collins won a fractured eight-way Republican primary only to be abandoned at first by conservatives for moderate social positions, then by moderates for King when her campaign faltered.

King often attacked Brennan from the right for raising certain taxes and challenging him to present specific ways to cut government spending. He eked out a win with 35 percent of votes to Brennan’s 34 percent, with Collins at 23 percent.

He followed that with a 40-point victory in 1998, winning over Frank O’Hara of Hallowell, a former Brennan speechwriter who later volunteered for King. O’Hara praised the independent governor for “going out on a limb” to pass the program giving Apple laptops to schoolchildren, though he said King sometimes “frustrated” some who thought he could be bolder because of his popularity.

“He generally was one that liked to build a consensus before action, which is why people all feel he’s listening to them,” O’Hara said.

Joseph Bruno, a Republican from Raymond who was House minority leader during the last two years of King’s term, called him an “old-school conservative Democrat who understood that businesses had to prosper,” saying he was “never fooled” by King’s independent designation.

But he conceded that King was able to “play both sides” in the Legislature because he was a popular governor.

“He never wanted to be the governor that couldn’t govern without a party,” Bruno said. “So, when he needed business help he went to the Republicans, and when he needed social causes help he went with the Democrats.”

In the Senate, he has voted like a conservative Democrat and kept the party largely happy while maintaining some flexibility. King made his return to politics in 2012 after U.S. Sen. Olympia Snowe’s abrupt retirement announcement, easily winning 53 percent of votes to defeat Republican Charlie Summers and Democrat Cynthia Dill, the latter of whom was abandoned by her party and got just 13 percent of votes.

In the Senate, King has voted like a centrist Democrat. He was the seventh-most conservative member of the Democratic caucus, according to National Journal ratings from the last congressional session to be published in the 2018 edition of the Almanac of American Politics. GovTrack’s analysis of sponsored bills rates him eighth in the caucus this year.

But King’s unaffiliated status allows him to do things Democrats can’t. In 2000, he endorsed Republican George W. Bush for president. He has endorsed Democrats for president and most other offices ever since, but he backed Collins in her landslide re-election in 2014.

He also has little appetite for obstruction, voting for 12 of President Donald Trump’s 18 Cabinet nominees, including Secretary of State Rex Tillerson, and refusing so far to go along with Democrats’ plan to filibuster U.S. Supreme Court nominee Neil Gorsuch.

“He’s really going to suss these things out by himself,” Dennis Bailey, a former spokesman for King, said. “Now, he has leanings toward the Democrats, so he may end up in the same place. But he’ll do it for a real reason.”

King hasn’t said how he’ll vote on Gorsuch, which will be a litmus test for progressives. Mainers for Accountability Leadership, a progressive group that has emerged to resist Trump, said in a news release last week directed at Collins and King that “we will make sure Mainers never forget that you sold out the women and LGBTQ Mainers” if they vote for Gorsuch.

Sen. Shenna Bellows, D-Manchester, who lost to Collins in 2014, said she hopes King will join Democrats to oppose Gorsuch but that Mainers will evaluate King on “the totality of his votes” and on social issues and civil liberties, “he has been a solid progressive.”

King will be hard to beat, but he hasn’t gotten his campaign apparatus far off the ground and Republicans sense an opportunity. By all measures, this is King’s seat to lose. He had a 63 percent approval rating in a Morning Consult survey released last year.

But the race is fraught with unknowns, including whether LePage will jump in, whether a Democrat will run and whether Maine’s new ranked-choice voting system will be up by 2018.

The governor has hemmed and hawed about running against King for nearly two years and said recently that it’s up to his wife, Ann. Bruno said anyone will have a hard time against King but that the combative LePage “has potential to beat him and beat him up.”

“He does not want to see Paul LePage run against him,” Bruno said of King, “because, you know, the governor’s going to come out swinging … and all you need to do is land one big one.”

If LePage does run, Democratic higher-ups could look to avoid the type of three-way race that they have blamed for LePage’s two victories. They couldn’t stop a candidate from running, but they could shut off help in gathering signatures that qualify a challenger for the ballot.

Maine Democratic Party Chairman Phil Bartlett said many in his party are “pleased” with King, saying the party will evaluate how to approach the race and that he has urged the senator to “reach out to Democrats about why they should support him.”

Brakey, a second-term legislator and libertarian who formed a committee to explore running against King last month, said the senator hasn’t lived up to his independent status, calling it a “shtick” and saying he has won elections facing “wishy-washy” opposition.

“Maybe if you were to put up another cardboard, cookie-cutter politician to run against him, I don’t think that person would have a chance,” he said. “But I think if you put someone up against him who has actual principles, who has an actual message, who actually believes in something, I think that’s what makes the difference.”

King is also trying to deflect political talk, with spokesman Scott Ogden saying in a statement that “it’s time to govern, not focus on an election that’s two years away” and “Maine people are looking to Angus for steady, principled and common-sense leadership and that’s what he’s delivering.”

Bailey said King “doesn’t like campaigning,” never did and always directed his staff to “just get me there” because he “wants to govern.” But he said King doesn’t take races for granted.

Then, he recounted a recent dinner with his former boss, where Bailey said the senator dusted off a quote from a colleague: “Unless you’re running unopposed, you run scared.”

CORRECTION:

An earlier version of this report misidentified the group Mainers for Accountable Leadership.